The present invention relates to a semiconductor device, and particularly to a semiconductor device incorporating a successive approximation analog-to-digital (AD) converter.
Recently, to achieve more accurate control, the resolution of a successive approximation AD converter (ADC) incorporated in a microcontroller or the like has been increasing. To achieve high-accuracy AD conversion, it is important to confirm that the AD converter maintains the initial accuracy.
In the related art, to confirm the accuracy of the AD converter in actual use, it is necessary to prepare a dedicated evaluation program and environment. More specifically, a high-accuracy external input voltage or internal reference voltage is provided as analog input to an AD converter, and the conversion result (code) of AD-converting this analog input voltage is compared with an expected value, so that the AD conversion accuracy is confirmed (e.g., Japanese Unexamined Patent Publication No. 2011-41231 (Patent Document 1) and Japanese Unexamined Patent Publication No. 2001-24509 (Patent Document 2)).